Influence of Twinning on the Constitutive Reponses of Zr : Experirnents and Modeling

Chen, Shuh Rong; Gray, George T.

doi:10.1051/jp4:19973126

Cited by 12 publications

(12 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…An axisymmetric mesh with a total of 21,120 cells (165 TT cells, 8 radial cells and 16 azimuthal cells) was generated with the sample modeled as a two-material (specimen and ring) composite. The specimen material forms the 10 mm central plug pressed into an outer ring of material having potentially different elastoplastic properties due to textural and other microstructural differences (12). Stress wave reflection from the plug/ring interface due to property discontinuity could affect the wave profile results, but a radial transit time of 1.05 µs for the plug precludes any such effect during the HEL loading phase.…”

Section: Hugoniot Elastic Limit Analysismentioning

confidence: 99%

Influence of crystallographic anisotropy on the Hopkinson fracture “spallation” of zirconium

Gray¹,

Bourne²,

Zocher³

et al. 2000

AIP Conference Proceedings

Self Cite

View full text Add to dashboard Cite

The influence of texture on the spallation (Hopkinson fracture) of low-symmetry metals (e.g. Zr, U, or Sn) has seen limited study. In this study, the Hopkinson fracture of annealed, high-purity Zr has been probed as a function of crystallographic texture. The quasi-static yield strength of the Zr studied is ≈2.5x higher in the plate's through-thickness direction compared to that measured in-plane due to a pronounced basal texture. The pullback signals of each orientation shocked to 5 GPa were found to be insensitive to the texture, although the HEL's and the soft-recovered, incipiently-spalled samples exhibited differences in their damage evolution. The VISAR wave profiles were modeled using a 3-D finite-volume method (FVM) continuum code. The VISAR, post-spallation metallographic observations, and modeling analysis are discussed with reference to the HEL and texture.

show abstract

Section: Hugoniot Elastic Limit Analysismentioning

confidence: 99%

Influence of crystallographic anisotropy on the Hopkinson fracture “spallation” of zirconium

Gray¹,

Bourne²,

Zocher³

et al. 2000

AIP Conference Proceedings

Self Cite

View full text Add to dashboard Cite

show abstract

“…It also is a critically important nuclear material in that the Zircaloy alloy (Zircaloy-2: Zr-1.5Sn-0.15Fe-0.1Cr-0.05Ni) is widely used as nuclear fuel cladding due to its combination of good corrosion resistance and low neutron absorption [11]. Table 10.11 lists several data sets that are considered here [12][13][14][15][16]. Pure zirconium has an HCP structure (alpha) at temperatures below 1143 K (T H = 0.538); above this temperature, a transformation to the BCC (beta) structure occurs.…”

Section: Pure Zirconiummentioning

confidence: 99%

“…Chen and Gray [15] reported full stress-strain curves in pure zirconium over a wide range of temperature and strain rates (see Table 10.11). Strain hardening-or structure evolution-is analyzed using Equation (9.7), with obstacles 1 and 2 instead of p and i in an identical manner as was demonstrated in pure magnesium (Figure 10.19).…”

Section: Structure Evolution In Zirconiummentioning

confidence: 99%

See 1 more Smart Citation

Application to HCP Metals and Alloys

2014

Fundamentals of Strength

View full text Add to dashboard Cite

Section 3.3 summarized several unique characteristics of slip in hexagonal close-packed (HCP) metals. In particular, the close-packed system-the basal plane (0001) and the close-packed direction < > 1120 -has only three independent systems compared with the 12 available in the face-centered cubic (FCC) crystal structure. Therefore, slip is observed on other crystal planes. The prismatic plane was referred to in Section 3.3. In the Miller-Bravais coordinate system, this is the ( ) 1010 plane and the close-packed direction < > 1120 . Slip is also observed on the pyramidal system, which is ( ) 1011 plane and, once again, the close-packed direction < > 1120 . The ease of slip in HCP metals as influenced by the dislocation energy and the spacing between parallel slip planes (as discussed in Section 3.2 in regard to the Peierls stress) is affected by the active slip system(s). One implication of this is that one should expect less commonality between in deformation kinetics in HCP metals than observed in FCC and body-centered cubic (BCC) metals.In this chapter, the temperature dependence and, in some cases, the strainrate dependence of deformation in pure Cd, Ti, Zn, and Zr and in Mg, Zr, and Ti alloys is examined. The analysis presented in these HCP metals is complicated by (1) the limited availability of extensive experimental campaigns available for model FCC and BCC systems, (2) contributions of deformation twinning observed in most of the HCP systems-particularly at low (homolo-Fundamentals of Strength: Principles, Experiment, and Applications of an Internal State Variable Constitutive Formulation, First Edition. Paul S. Follansbee.

show abstract

“…Material: Pure Zr Grain size ¼ 1 mm Driving forces from Thermo-Calc software, PURE database: 128, 234, 346, 433, 505, 568 and 629 J/mol at 300 K, 373 K, 473 K, 573 K, 673 K, 773 K and 873 K, respectively [42] Thermodynamic coefficients: A ¼ 2376 J/mol, B ¼ 7128 J/mol, C ¼ 4752 J/mol [14] Gradient coefficient (b) ¼ 1.06066 x 0 À11 J/m [14] Molar volume (V m ) ¼ 14 x 10 À6 m 3 /mol Interface thickness (d) ¼ 1 nm [14] Interfacial energy (g) ¼ 0.01 J/m 2 [14] Lattice constants: a a ¼ 3.232 Å, c a ¼ 5.147 Å, a u ¼ 5.039 Å, c u ¼ 3.136 Å [38,43]. Shear modulus (G) ¼ 36.3 GPa [44], Poisson ratio (n) ¼ 0.331 [44] Yield stresses: s a y ¼ 180 MPa, s u y ¼ 1180 MPa [45] Hardening modulus (H) ¼ 1300 MPa[46] Plastic relaxation rate (k)¼ 10 GPa À1 s À1 Interfacial kinetic coefficient (L) ¼ 1 m 3 J À1 s À1observed that the entire a grain transforms into an u grain when Zr is soaked for 24 h[2].Rabinkin et al have observed ellipsoidal u particles in Zr when soaked under pressure for 4 h, a morphology that can be observed during the b À u phase transformation in ZreNb alloys…”

mentioning

confidence: 99%

Alpha – omega and omega – alpha phase transformations in zirconium under hydrostatic pressure: A 3D mesoscale study

2016

View full text Add to dashboard Cite

a b s t r a c tA three dimensional (3D) elastoplastic phase-field model is developed for modeling the hydrostatic pressure-induced alpha e omega phase transformation and the reverse phase transformation, i.e. omega e alpha, in zirconium (Zr). Plastic deformation and strain hardening of the material are also considered in the model. The microstructure evolution during both phase transformations is studied. The transformation start pressures at different temperatures are predicted and are plotted as a phase diagram. The effect of phase transformations on the mechanical properties of the material is also studied. The input data corresponding to pure Zr are acquired from experimental studies as well as by using the CALPHAD method. Our simulations show that three different omega variants form as laths. On release of pressure, reverse phase transformation initiates at lath boundaries. We observe that both phase transformations are martensitic in nature and also occur at the same pressure, i.e. little hysteresis. The transformation start pressures and the kinetics of the transformation predicted by our model are in good agreement with experimental results.

show abstract

Influence of Twinning on the Constitutive Reponses of Zr : Experirnents and Modeling

Cited by 12 publications

References 7 publications

Influence of crystallographic anisotropy on the Hopkinson fracture “spallation” of zirconium

Influence of crystallographic anisotropy on the Hopkinson fracture “spallation” of zirconium

Application to HCP Metals and Alloys

Alpha – omega and omega – alpha phase transformations in zirconium under hydrostatic pressure: A 3D mesoscale study

Contact Info

Product

Resources

About